Paraceratherium

Paraceratherium
Temporal range: Oligocene, 34–23 Ma
Mounted P. transouralicum skeleton, Moscow Paleontological Museum; this is the most completely known skeleton, but the skull is a cast of a specimen at the American Museum of Natural History[1]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Perissodactyla
Family: Paraceratheriidae
Genus: Paraceratherium
Forster-Cooper, 1911
Type species
Aceratherium bugtiense
Pilgrim, 1908
Species
  • P. bugtiense (Pilgrim, 1908)
  • P. transouralicum (Pavlova, 1922)
  • P. huangheense Li et al., 2017
  • P. linxiaense Deng et al., 2021
Synonyms
Genus synonymy
  • Baluchitherium Forster-Cooper, 1913
  • Indricotherium Borissiak, 1916
  • Pristinotherium Birkjukov, 1953
  • ?Benaratherium Gabunia, 1955
Species synonymy
  • P. bugtiense:
  • Aceratherium bugtiense Pilgrim, 1908
  • Thaumastotherium osborni Forster-Cooper, 1913 (preoccupied)
  • Baluchitherium osborni (Forster-Cooper, 1913)
  • Metamynodon bugtiensis Forster-Cooper, 1922
  • Paraceratherium zhajremensis Bayshashov, 1988
  • P. transouralicum:
  • Indricotherium transouralicum Pavlova, 1922
  • Baluchitherium grangeri Osborn, 1923
  • Indricotherium asiaticum Borissiak, 1923
  • Indricotherium minus Borissiak, 1923
  • Indricotherium grangeri (Osborn, 1923)
  • Pristinotherium brevicervicale Birjukov, 1953
  • Dubious names:
  • Benaratherium callistratum Gabunia, 1955

Paraceratherium is an extinct genus of hornless rhinocerotoids belonging to the family Paraceratheriidae. It is one of the largest terrestrial mammals that has ever existed and lived from the early to late Oligocene epoch (34–23 million years ago). The first fossils were discovered in what is now Pakistan, and remains have been found across Eurasia between China and the Balkans. Paraceratherium means "near the hornless beast", in reference to Aceratherium, the genus in which the type species P. bugtiense was originally placed.

The exact size of Paraceratherium is unknown because of the incompleteness of the fossils. The shoulder height was about 4.8 metres (15.7 feet), and the length about 7.4 metres (24.3 feet). Its weight is estimated to have been about 15 to 20 tonnes (33,000 to 44,000 lb). The long neck supported a skull that was about 1.3 metres (4.3 ft) long. It had large, tusk-like incisors and a nasal incision that suggests it had a prehensile upper lip or proboscis (trunk). The legs were long and pillar-like. The lifestyle of Paraceratherium may have been similar to that of modern large mammals such as the elephants and extant rhinoceroses. Because of its size, it would have had few predators and a long gestation period. It was a browser, eating mainly leaves, soft plants, and shrubs. It lived in habitats ranging from arid deserts with a few scattered trees to subtropical forests. The reasons for the animal's extinction are unknown, but various factors have been proposed.

The taxonomy of the genus and the species within has a long and complicated history. Other genera of Oligocene indricotheres, such as Baluchitherium, Indricotherium, and Pristinotherium, have been named, but no complete specimens exist, making comparison and classification difficult. Most modern scientists consider these genera to be junior synonyms of Paraceratherium, and it is thought to contain the following species; P. bugtiense, P. transouralicum, P. huangheense, and P. linxiaense. The most completely-known species is P. transouralicum, so most reconstructions of the genus are based on it. Differences between P. bugtiense and P. transouralicum may be due to sexual dimorphism, which would make them the same species.

  1. ^ Cite error: The named reference Prothero 2013 17 34 was invoked but never defined (see the help page).